Rotary engine



2 Sheets-Sheet 1.

(No Model.) V E. s. BAOH.

ROTARY ENGINE.

No. 549,484. I Patented NOV. 12, 1895.

UNITED STATES PATENT OFFICE.

EINAR SEBASTIAN BACH, OF COLORADO CITY, COLORADO.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 549,484, dated November12, 1895.

I Application filed JanuaryZ, 1895. Serial No. 533,547. (No model.)

To all whom it may concern:

vBeit known that I, EINAR SEBASTIAN BAoH, a citizen of the UnitedStates, residing at Colo-v rado City, in the county of El Paso and Stateof Colorado, have invented certain new and useful Improvements in RotaryEngines; and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the letters of reference markedthereon, which form a part of this specification.

My invention relates to rotary engines, and its object is to provide animproved engine or motor of this class adapted to be operated by steam,compressed air, water, or any other fiuid under pressure and of greaterefficiency than those with which I am acquainted.

The invention consists in certain constructions and arrangements ofparts, hereinafter a side elevation with one end of the casing removed.Fig. 2 is also an end elevation, the valve-chest being in section. Fig.3 is a top plan partly in section. Fig. 4 is a vertical section on line4 4., Figs. 1 and 2. detail.

The casing is composed of a preferably-cylindrical body A and heads A Asecured to said body by screws a, the joints being made fluid-tight inany desired way. Legs A may be cast with or attached to the heads. Theinterior of the body A is elliptical in shape, though not a trueellipse. The ends from a to a and a to a are arcs (preferably of abouteighty degrees) of a circle struck from the axis of the transverse shaft13. The sides are formed by continuing the curve of the ends in aparabolic curve, the two parabolas on each side meeting in a commontangent at the minor axis of the ellipse.

Secured to the shaft B within the casing is a cylindrical wheel C,having a hub c, a rim 0, and arms or spokes 0 the latter beingpreferably double, as shown. The rim and arms are slotted to receive theflat sliding pistons or abutments l) D D Those portions of the rimbetween the slots have a groove in their edges to receive the packing-Fig. 5 is a.

strip 0 which is kept pressed out by any suitable means against thesmooth plane inner faces of the heads A A of the casing. The pistons,which are preferably three in number, are each provided with groovededges and outer ends to receive the packingstrips (1. A spring E isprovided for each piston, one end being held in a socket c on the wheelO and the other end bearing against the inner end of the piston andtending to force it outwardly.

The end of the piston may be notched to keep the spring in place. Ineach piston are one or more pins or studs 61, which when the pistonreaches the limit of its outward movement bring up against the shouldersc on the arms c and thus positively stop the piston from further outwardmovement. These stop-pins are so placed that the ends of the piston donot touch the casing between the points a (1- the joint being kept tightby the packing d.

The rim 0 of the wheel comes close to the sides of the casing on theminor axis of the ellipsethat is to say, about midway between the pointsa a and a a the slight space be tween them being kept fluid-tight bymeans of the hinged packing-plates F, let into recesses in the body Aand held against the rim 0 by the springs f.

Steam or other fluid under pressure is supplied to a valve-chest G,secured to the head A and surrounding the shaft B, which passes throughstufliing-boxes G and G on the valvechest and the head A respectively.In the A are cored out two passages II H, which open at one end into thevalve-chest by the ports h h, located diametrically opposite on eitherside of the shaft in a preferably flat valve-seat g. The other ends ofthe passages H H, communicate with transverse passages H H cored out inthe body A at points on or near the minor axis of the elliptical casing.Each of these transverse passages has one or more narrow ports 71, hopening into the spaces 00 y between the rim of the cylindrical wheel 0and the ends of the elliptical chamber in the body A, the ports 7L2leading to the upper space x and the ports h to the lower space y, asshown in Fig. l, and in each case in advance of the adjacentpacking-plate F. The body A has a recess a at the points where the portsIL2 71.3 enter it, as shown by the dotted lines in Fig. 1 and inperspective in Fig. 5, thereby enlarging the spaces a: y and affording achamber to be filled with the fluid as soon as it is admitted and havinga should er a radial to the shaft and serving as a stationary abutmentfor the fluid to act against. The pistons do not enter this recess,being compelled to slide on the edges a thereof. The backs of therecesses a merge into the elliptical curve of the chamber in the body Aat the points a a At the opposite end of each space my there is asimilar recess a with which communicate the two exhaust-ports 2', whichlead, preferably, to a common exhaust-passage I, cored out in the head AThe admission of the actuating fluid is controlled by a rotatingwalve K,preferably in the form of a disk keyed upon the shaft B within thevalve-chest G, and held against the valve-seat g by the pressure of thefluid. The holes in the hub of the valve through which the key 1) passesare elongated, so that the disk is capable of a slight axial motion onthe shaft and, being thus loose, is kept pressed tight against thevalve-seat.

In the disk valve are three ports 7a 7c k spaced at equal distancesapart, like the three pistons. The ports and pistons have a certainrelative position, which will clearly appear upon an inspection of Figs.1 and 2. The arrangement is such that just as the piston D passes thepoint a, as shown in Fig. 1, the pot h is uncovered by the port 7t,admitting the fluid pressure to the passages H H ports 7L2, and chambera, where it exerts its force against the pistons. At the same instantthe piston B is about midway between the points a a and the piston D hastraversed most of the space y and is nearly at the point a the beginningof its exhaust. As soon as it reaches that point the port it will beentirely closed, the forward movement of the disk K having carried theport k away from the.

port h. As soon as the piston D reaches the point a the port It willbegin to open the port 72, and the port to close the port It. The fluidis thus admitted to the passages H H alternately and the pistons areacted upon alternately in the spaces 00 and 11 Since the arcs from a toa and a to a are concentric with the shaft, the pistons have no radialmovement while subjected to the fluid-pressure; but as soon as theyreach the point a or a and begin to be forced inwardly by the flattenedparabolic curves of the casing then the exhaust-port opens and relievesthe pressure. The pistons, therefore, are not subjected to anyunbalanced pressure while sliding in or out in the slotted arms 0 andthe only resistance to be overcome by the cam action of the casingbetween the points a a and a a is that of the spring E, which need beonly strong enough to overcome the weight of the piston, so as to assistin its outward movement. This construction greatly reduces the wear andenhances the easy and rapid running of the motor. Another importantfeature in this con nection is the position of the pistons, which arenot radial, but tangent to the shaft B or to a small circle concentricwith the shaft. This inclines them forward, which not only brings themmore nearly normal to the flattened curves a a and a a and so renders iteasier for them to be forced inwardly by said curves, but alsocounteracts to a certain extent the effect of centrifugal force, whichtends to throw the pistons out against the inner surface of the casing.Any loss which might be due to their not standing at right angles to thecolumn of actuating fluid is made up by the increased surface presentedto the pressure. The particular position of the pistons must be governedby the speed at which the motor is to run, since the greater the speedthe larger must be the circle to which they are tangent, or, in otherwords, the greater must be their departure from a radial position.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. In a rotary engine, a casing having its ends composed of arcs a a aa, concentric with the shaft, and sides composed of parabolic arcsmeeting in a common tangent midway between the ends, said sides havingrecesses a with radial ends a and terminating at the points a a andrecesses a beginning at the points a a with inlet ports 7L2 7L3 in theends a of the recesses a and exhaust ports 2' opening into and coveringone end of the recesses a substantially as described.

2. In a rotary engine, the combination with the casing A having anelliptical interior with ends concentric with the shaft B, of acylindrical wheel 0 mounted on the shaft, having arms 0 each inclinedforward at an angle with the radial line, said arms and the rim beingslotted from one side to the other, sliding pistons D mounted in saidslots, and spring rods E each having one end fastened to the wheel 0 andthe other end bearing against the inner end of a piston D, substantiallyas described.

3. In a rotary engine, the combination with a casin g A, having anelliptical interior with concentric ends, of a wheel C having slotteddouble arms 0 provided with shoulders 0", pistons D sliding in the slotsand carrying pins (1 sliding along the inner edges of the arms 0 andadapted to abut against said shoulders, and spring rods E, each havingone end inserted in a socket c on the wheel, and the other end restingagainst the inner end of a piston between the double arms 0substantially as described.

In testimony whereof I afiix my signature in presence of two witnesses.

EINAR SEBASTIAN BACII.

\Vitnesses:

LUTE M FIELD, JOHN F. MORGAN.

